City cops issued an astonishing 32 percent fewer traffic tickets last week compared to the same period a year ago — after being threatened with the loss of vacation days if they botched any moving-violation cases.

Just over 11,230 summonses for moving violations handed out to motorists, as opposed to 16,695 for the same week in 2010.

The drastic decline came less than two weeks after The Post reported that NYPD brass — furious over the department’s embarrassing ticket-fixing scandal — mandated that cops would be docked 10 vacation days if any of their cases fell apart because of a procedural flub.

“Why should I want to write a summons to put myself in jeopardy of losing 10 days’ vacation?” one cop asked The Post.

Last week’s drop in summonses was so sharp that Police Commissioner Ray Kelly personally called NYPD Transportation Bureau Chief James Tuller demanding to know why it had occurred, one source said.

Ironically, Tuller has himself been questioned for allegedly trying to fix a ticket for his brother-in-law.